Highly ordered titania nanotube (TNT) arrays were fabricated by anodic oxidation of titanium foil followed by CO annealing. The lithium-ion intercalation capacities of the as-prepared sample was studied and found to be improved a lot compared with not only the unannealed arrays but also the arrays annealed in nitrogen. The initial discharge capacity was as high as 360 mAh/g and the cycle stability was also very good. X-ray Photoelectron Spectra (XPS) and the results show that annealing in CO can create Ti3+ defect and carbon-doping on TiO2 nanotube surface. The high lithium-ion storage capacity could be attributed to the greatly improved conductivity induced by Ti3+ defect and carbon-doping